[Offline indicator v2] Add field trial testing entry

Bug: 1091491
Change-Id: Ieba9919f7c1363b5b39ca33081e2c84b6d166bd2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2358434Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/master@{#801218}

testing/variations/fieldtrial_testing_config.json

@@ -4439,6 +4439,21 @@
             ]
         }
     ],
+    "OfflineIndicatorV2": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "OfflineIndicatorV2"
+                    ]
+                }
+            ]
+        }
+    ],
     "OfflinePagesCctV2": [
         {
             "platforms": [